For those who want to explore the waters below without getting wet there are
number of submarine and glass bottomed boats offering tours of the reef.

Nautibus is a glass-bottomed boat where you sit just under the water for a
sightseeing tour of the local Cancun reef. Tours leave at 9:30 AM, 11 AM, 12:30
PM and 2:00 PM.

Atlantis is a submarine that goes completely underwater to tour the reefs close
to Isla Mujeres. The tour includes the 45-minute underwater with a stopover at
Playa Indios (also on Isla) for an all-you-can-eat food and drink buffet at the
Atlantis Bar & Grill. Showers, towels, and locker service are included.
Contact Aqua Tours. Blvd. Kukulcán, Km 6. Tel: (998) 883-0227.